From: Chris Mason <chris.mason@oracle.com>
Date: Tue, 3 Apr 2007 15:43:19 +0000 (-0400)
Subject: Btrfs: don't wait on uptodate buffers on read
X-Git-Tag: firefly_0821_release~15789^2~11^2~55^2~56^2~30^2~622
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9d64272cd3be2aae71f89f7ababbee90a7587b33;p=firefly-linux-kernel-4.4.55.git

Btrfs: don't wait on uptodate buffers on read

Signed-off-by: Chris Mason <chris.mason@oracle.com>
---

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 39b117a57a54..055cd45e802e 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -214,6 +214,8 @@ struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
 	bh = btrfs_find_create_tree_block(root, blocknr);
 	if (!bh)
 		return bh;
+	if (buffer_uptodate(bh))
+		goto uptodate;
 	lock_buffer(bh);
 	if (!buffer_uptodate(bh)) {
 		get_bh(bh);
@@ -226,6 +228,7 @@ struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr)
 	} else {
 		unlock_buffer(bh);
 	}
+uptodate:
 	if (check_tree_block(root, bh))
 		BUG();
 	return bh;